1. Field of the Invention
The present invention relates to a DC-DC converter, and in particular relates to a ZCS-PFM (zero current switching and pulse frequency modulation) DC-DC converter in DCM (discontinuous condition mode).
2. Description of the Related Art
A DC-DC converter is an electronic circuit which converts a direct current (DC) source from one voltage level to another. Switched-mode conversion is commonly used to realize a DC-DC converter, which converts one DC voltage level to another by storing the input energy temporarily and then releasing that energy so that it is outputted. The storage component may be a magnetic field storage component (inductors, transformers) or an electric field storage component (capacitors). Switches are provided so that energy may be transmitted into the storage component or be outputted therefrom.
Drawbacks of a switched-mode DC-DC converter include power dissipation cased by the switching operations and EMI (electromagnetic interference).